Infrared burners are used for efficiently heating various solid objects and fluids including air, water and oil. During their manufacture, assembly of the various components poses certain problems. A radiant burner typically consists of a ceramic tile or a plurality of ceramic tiles which are supported within a gas mixing plenum. The ceramic tile or tiles may be secured within the plenum by various means such as cementing or employing spokes between the ceramic tiles. These techniques rigidly secure the tiles and do not allow the flexibility which is needed to withstand thermal and physical shock and to effectively seal the juncture of the ceramic tile and the plenum. To alleviate this problem, a flexible tile retainer means may be used to secure the ceramic tile within the plenum. Typically, a cloth-like refractory material gasket is cushioned between the tile retainer means and the ceramic tile edges to help absorb possible thermal and physical shock to the burner assembly, thereby reducing damage. A usual tile retainer has a ceramic tile edge engaging portion and a depending transverse portion where the retainer is attached to the plenum by a mechanical fastening means. In the past, these mechanical fastening means have included nut and bolt attachments, rivets, or screw attachments.
In the past, conventional infrared burners have been manufactured by including mechanical fastening means between the tile retainer and the plenum which contains the burner tile. As discussed below, there have been many attempts to design new infrared burner assemblies for greater efficiency and ease of manufacture. In the prior art, mechanisms such as nuts and bolts, rivets, or screws have been utilized to secure the tile retainer to the outer plenum lip. During assembly, it has been found that manufacturers using a nut and bolt system require several minutes per infrared burner to assemble. For those manufacturers utilizing rivets or screws attaching to complementary mated threads, assembly takes more than about one minute per burner.
During the manufacture of infrared burners, the burner tile component is merely dropped into the plenum and then the tile retainer acts to secure the burner tile within the plenum. Until now, the manufacture of these burner assemblies has included the use of many workers to hand tighten the nuts and bolts or screws which secure the tile retainer to the plenum. The following patents disclose various prior art means and methods for securing the tile retainer to the plenum.
U.S. Pat. No. 4,035,132 issued on Jul. 12, 1977 to Smith discloses a radiant heater having a supported porous refractory panel through which combustion mixture passes and burns. The patent further discloses a gas-fired radiant heater which reduces the likelihood of backflashing by including a tubular frame for supporting a porous refractory panel. Upper frame members are included which have upper flanges overlying the outer face of the porous refractory panel. The flanges of the frame members are secured to a lower frame member by a screw attachment means.
U.S. Pat. No. 3,556,707 issued on Jun. 5, 1969 to Hine discloses a gas-fired radiant heater assembly having a plurality of porous ceramic tiles forming a radiant gas burning surface in which the tiles are supported on two parallel longitudinally extending metal shelves. Each support shelf is secured to a respective longer side of a rectangular frame member that is removably attached to the opening of the heater body, specifically depicted in the drawings as a threaded nut and bolt.
U.S. Pat. No. 3,824,064 issued on Jul. 16, 1974 to Bratko discloses an infrared process burner comprised of individual sections rigidly fastened together to provide an elongated unit having a common continuous burner face. A tile retaining rim is disclosed for securing the sections and includes a face engaging portion acting as a lip, and an upright section made from angle iron. Extending upwardly from the upright section and at intervals therearound are studs having threaded ends thereon, adapted to be received in suitable ears fastened to sides of a burner body. The application of nuts is contemplated to keep the tile retaining rim in place and thereby retains the burner face in position over the openings of the burner body.
Accordingly, it would be advantageous to provide a tile retainer design that is adapted for automatically securing and sealing burner tiles within the plenum of a gas fired infrared burner. Such a tile retainer design would help to lend automated assembly to the production of infrared burner assemblies.
It would be further advantageous to provide a tile retainer design that would help to maintain a spring-like pressure to retain a substantially gas tight seal between the ceramic tile and the plenum over the service life of the gas fired infrared burner. Conventional mechanical fastening means have included nuts and bolts, rivets, and screws which are substantially fixed in place and do not allow for movement with the expansion and contraction of the burner assembly during service.
It is therefore an object of the present invention to provide an infrared burner tile retainer for securing and sealing a burner tile within a plenum by a plurality of tabs extending downwardly from the tile retainer so that the tabs may be bent underneath the plenum lip by automated equipment to form an entire manufactured unit without having to use mechanical fastening means such as nuts and bolts or screws which are time consuming and difficult to automate.
It is another object of the present invention to provide a one-piece cut-and-form stamped tile retainer that may be made of stainless steel, aluminized stainless steel, or any other sheet material which exhibits heat resistivity and low creep characteristics.